CBSE Class 6 Science Chapter 7 Notes — Getting to Know Plants

Types of Plants

1. Herbs

• Small plants with soft, green stems.
• Usually short-lived.
• Examples: Wheat, grass, tomato, mint, coriander, tulsi.

2. Shrubs

• Medium-sized plants with hard, woody stems that branch near the base.
• Live for several years.
• Examples: Rose, jasmine, lemon, henna (mehndi), cotton.

3. Trees

• Tall plants with a single thick, hard trunk that branches higher up.
• Live for many years (some for hundreds of years).
• Examples: Mango, neem, banyan, teak, oak.

4. Climbers

• Weak-stemmed plants that take support of other plants or objects and climb upward.
• Examples: Grapevine, money plant, pea, bougainvillea.

5. Creepers

• Plants with weak stems that spread along the ground.
• Examples: Watermelon, pumpkin, sweet potato.

Root System

Roots anchor the plant and absorb water and minerals from the soil.

Taproot

• One main thick root going deep into the soil.
• Smaller roots (lateral roots) grow from the sides.
• Found in dicot plants (broad-leaved plants).
• Examples: Mango, rose, mustard, carrot (taproot used as food).

Fibrous Root

• Many thin roots of similar size forming a bundle.
• No single main root.
• Found in monocot plants (narrow-leaved plants).
• Examples: Wheat, grass, rice, onion, maize.

Functions of Roots

1. Anchor the plant firmly in the soil. 2. Absorb water and dissolved minerals. 3. Some roots store food — carrot, radish (modified roots).

Stem

Functions of Stem

1. Supports leaves, flowers, and fruits. 2. Transports water and minerals upward from roots to leaves. 3. Transports food downward from leaves to other parts. 4. Some stems store food — potato, sugarcane, ginger.

Activity to Show Transport in Stem

• Place a white carnation (or celery stalk) in coloured water.
• After a few hours, the petals/leaves show the colour of the water.
• This proves water travels up the stem.

Leaf

Parts of a Leaf

1. Lamina (blade) — flat, broad part of the leaf. 2. Petiole — stalk that connects leaf to the stem. 3. Veins — network of lines on the leaf surface; transport water and food. 4. Midrib — main thick vein running through the centre.

Types of Venation (Arrangement of Veins)

Trick: Reticulate venation → dicot plants (broad leaves). Parallel venation → monocot plants (narrow leaves).

Functions of Leaves

1. Photosynthesis — make food using sunlight, water, CO₂. 2. Transpiration — release excess water as vapour through tiny pores (stomata). 3. Some leaves store food — onion (fleshy leaves), aloe vera.

Flower

• Flower is the reproductive part of a plant.
• Main parts of a flower:
• Sepals — green leaf-like parts that protect the bud.
• Petals — coloured parts that attract insects.
• Stamens — male reproductive parts; produce pollen.
• Pistil (Carpel) — female reproductive part; contains the ovary.

Photosynthesis (Introduction)

• Leaves make food using sunlight, water, and CO₂.
• Chlorophyll (green pigment) in leaves helps capture sunlight.
• Oxygen is released as a by-product.

Simple equation: Water + Carbon dioxide → Food (glucose) + Oxygen (in presence of sunlight)

Key Vocabulary

Exam Tips

• Herb vs Shrub vs Tree table is almost always tested — learn 2 examples each.
• Taproot vs Fibrous root — connect to dicot/monocot (even at Class 6 level, this distinction helps).
• Reticulate = net-like = broad leaves. Parallel = parallel = narrow (grass-like) leaves.
• For transport in stem question, describe the coloured water experiment.
• Functions of leaves: photosynthesis, transpiration, food storage (for some).